Disposable absorbent articles, such as diapers, are designed to contain bodily exudates, such as urine, to prevent the soiling of the wearer's clothing and/or other items (for example, a bed, a chair, a blanket, etc.). The fit of the article to the wearer's body is important in ensuring that these wastes are contained, instead of leaking out. The fit of the article to the wearer's body may be affected by the size of the diaper waist opening, the size of the openings around the thighs, and the length or “pitch” of the diaper.
Disposable absorbent articles are also designed to be cost-effective. That is, the average consumer may have second thoughts about using a product that holds itself out as disposable if the cost per article is too high. Thus, manufacturers generally make such articles for use by individuals with a wide range of body types that may be classified by a broad criterion, such as weight, for example.
It will be recognized that the need to make products that conform to a wide range of body types competes with the desire for the article to fit snugly to the user to contain wastes and limit leakage.
One way in which manufacturers attempt to balance the competing interests of proper fit and variation in body type is through the use of expandable materials. One such group of materials is known as stretch laminates. As the name suggests, these materials are actually composites of individual components that are laminated together, through the use of an adhesive, for example. A typical stretch laminate will attempt to combine an inner layer defined by a material having good elastomeric properties, to accommodate varying body types, with outer layer or layers defined by a fabric-like material, to accommodate user expectations for look and feel.
A complication arises in that the outer layer or layers of these stretch laminates may inhibit the operation of the inner layer having good elasticity. Consequently, stretch laminates often undergo a processing step, known as activation, prior to use in the manufacture of an absorbent article, such as a diaper or pant, for example. During activation, a mechanical deformation is imposed on the laminate so that the composite material will exhibit better elasticity, while providing the desired look and feel.
Unfortunately, the activation process may have unintended consequences for the materials that comprise the laminate. For example, mechanical damage to the inner, elastomer layer, as manifest by ruptures or holes in the elastomer, may occur during the activation process. These holes may be macroscopic, and may be on the order of several millimeters in size. If an excessive number of holes develop, the laminate material may be perceived by the user as defective, or may not provide the desired stretch properties or performance.
One solution has been to use larger thicknesses, or gauges, of material for the inner layer. Another alternative has been to use specialty nonwoven products, designed and manufactured to be compatible with the activation (or ring-rolling) process, for the outer layers. Both of these solutions increase the cost of the resultant laminate.
Thus, it would be desirable to provide new stretch laminates and methods for making stretch laminates. In particular, it would be desirable to provide less expensive laminates produced using less expensive materials.